I'd like to know how shortly after returning from deployment the 3rd pictures were taken. Some of them appear to be taken during that phase when one transitions from active war to figuring out peace and home, but still vigilant/hypervigilant. Others appear to be after that transition when the emotional stuff has been (or begun) to be sorted out after holding it in check during deployment.
Regardles, it is a telling visualization of the transition from peacetime citizen/soldier to combat veteran. Unfortunately, I wonder just how much effort was put into getting shots of "the thousand-yard stare" as opposed to any other facial expression.
stay safe.
Maybe I'm bad at faces, but more than half of them didn't even seem that different to me, especially between the beginning and the end. The kind of Rorschach test where it says more about you than it does the pictures. About 3/4'ths of the middle pictures definitely look "flinty eyed" while in-country, but the beginning and end, not so much.
And how much would weight loss from the exercise of being deployed - patrolling etc., stress, or how they ate affect their faces rather than their actual emotional makeup? And the photoshopped blackout around their heads is problematic. From the pupil size, I can tell for sure the light conditions for the three pictures were not the same at all. Dilated pupils will generally make a person look more "invested" and "open", narrow ones make you look more "distant". Hell, just the lighting alone would do it to the rest of their face. Single source light with little fill would make anybody look more severe and gaunt.
Presumably these guys were all combat-arms, "outside the wire"-types, but the article is not explicit in confirming it either.
Actually, reading through the comments, I'm not alone in these questions.